Antiangiogenic Property Of Anacardic Acid And Establishment Of Retinopathy Of Prematurity (ROP) Model

1. Anacardic Acid Inhibits Tumor Growth and Tumor Angiogenesis by Targeting Src/FAK Signaling PathwayAngiogenesis is a process of forming new blood vessel by sprouting or imbedding from the existing capillary. It usually happens in embryo development, reproductive cycle and wound healing, but many pathological process, such as tumor, diabetic retinopathy, rheumatoid arthritis, psoriasis and atherosclerotic plaques, et.al, associate with angiogenesis. Anacardic acid (6-pentadecylsalicylic acid), a natural inhibitor of histone acetyltransferase from Ginkgo or cashew, has been implicated in anti-inflammatory, anticancer, antioxidative and antimicrobial functions. However, whether this salicylic acid could block angiogenesis or not has not been elucidated to date. Here, we postulated that anacardic acid affects multiple steps of tumor angiogenesis to contribute to its inhibition to solid tumor. In this study, we found that vascular endothelial growth factor (VEGF)-induced cell proliferation, migration, adhesion and capillary-like structure formation of primary cultured human umbilical vascular endothelial cells (HUVECs) could all be significantly suppressed by anacardic acid in vitro, without detectable cellular toxicity. Furthermore, anacardic acid effectively inhibited the vascular development in chick embryo chorioallantoic membrane ex vivo (n=10) and VEGF-triggered corneal neovascularization in vivo (n=10). Mechanistic study revealed that anacardic acid blocked activities of Src and FAK kinases in concentration-and time-dependent manners in HUVECs, resulting in downstream activation of RhoA-GTPase and inactivation of Racl-and Cdc42-GTPases. Notably, when subcutaneously administrated with anacardic acid (2 mg/kg·d) to mice bearing human prostate cancer xenografts after tumors reached～70mm3(n=6-7), the volume and weight of solid tumors were significantly retarded. CD31and Ki-67immunohistochemistry further showed that tumor microvessel density and cell proliferation could be remarkably suppressed by anacardic acid. Taken together, our findings demonstrated for the first time that anacardic acid functions as a potent tumor angiogenesis inhibitor by targeting Src/FAK signaling pathway, leading to significant suppression of tumor growth and tumor angiogenesis.2. Establishment of Retinopathy of Prematurity (ROP) modelThree common disease, diabetic retinopathy (DR), age-related macular degeneration (AMD) and retinopathy of prematurity (ROP), leads to human blindness. The leading cause of human blindness is pathological angiogenesis in the retina and choroid. In considering the angiogenesis drug screening required in our laboratory, I constructed retinopathy of prematurity model following literature review. We used gambogic acid as one of the tested compounds. First, postnatal day7(P7) mice were treated for5days by75%oxygen. Second, mice were kept in normal air, and at the same time, they were treated by the drug for5day. Third, fluorescein-conjugated dextran was perfused through heart. And then, eyes were removed from mice and fixed in4%paraformaldehyde at4℃over night. At last, the retinas were dissected and photographed by fluorescence microscope. The ROP model was establishment successfully. Following the above steps gambogic acid and oridonin could significantly suppressed retinal angiogenesis. This animal model is being used in our institute.